from opendc.models_old.experiment import Experiment
from opendc.models_old.machine_state import MachineState
from opendc.util import exceptions
from opendc.util.rest import Response


def GET(request):
    """Get this Experiment's Machine States."""

    # Make sure required parameters are there

    try:
        request.check_required_parameters(path={'experimentId': 'int'})

    except exceptions.ParameterError as e:
        return Response(400, str(e))

    # Instantiate an Experiment from the database

    experiment = Experiment.from_primary_key((request.params_path['experimentId'], ))

    # Make sure this Experiment exists

    if not experiment.exists():
        return Response(404, '{} not found.'.format(experiment))

    # Make sure this user is authorized to view this Experiment's Machine States

    if not experiment.google_id_has_at_least(request.google_id, 'VIEW'):
        return Response(403, 'Forbidden from viewing Machine States for {}.'.format(experiment))

    # Get and return the Machine States

    if 'tick' in request.params_query:
        machine_states = MachineState.from_experiment_id_and_tick(request.params_path['experimentId'],
                                                                  request.params_query['tick'])

    else:
        machine_states = MachineState.from_experiment_id(request.params_path['experimentId'])

    return Response(200, 'Successfully retrieved Machine States for {}.'.format(experiment),
                    [x.to_JSON() for x in machine_states])